private static TContent AddOrUpdateContentCache <TContent>(
INavigationRegistration registration)
where TContent : FrameworkElement
{
if (ContentCache.All(cachedPage => cachedPage.Type != registration.ViewType))
{
CreateCachedContent(registration);
}
var reference = ContentCache
.First(cachedPage => cachedPage.Type == registration.ViewType)
.Reference;
if (!reference.TryGetTarget(out FrameworkElement view))
{
view = GetContentInstance <TContent>(
registration);
reference.SetTarget(view);
}
return((TContent)view);
}
private static TPage AddOrUpdateContentCache <TPage>(
INavigationRegistration registration)
where TPage : Page
{
if (PageCache.All(cachedPage => cachedPage.Type != registration.ViewType))
{
CreateCachedPage(registration.ViewType);
}
var reference = PageCache
.First(cachedPage => cachedPage.Type == registration.ViewType)
.Reference;
if (!reference.TryGetTarget(out Page view))
{
view = GetViewInstance <TPage>(
registration);
reference.SetTarget(view);
}
return((TPage)view);
}
private static bool TryGetRegisteredViewModelType(
Type viewType,
out INavigationRegistration registration)
{
registration = NavigationRegistrations.FirstOrDefault(
registration => registration.ViewType == viewType);
return(registration != null);
}
/// <inheritdoc cref="CodeMonkeys.Navigation.INavigationService.Register(INavigationRegistration)" />
public void Register(INavigationRegistration registration)
{
RegisterInternal(registration);
if (registration.PreCreateInstance)
{
Task.Run(() => CreateCachedContent(registration));
}
Log?.Info($"Registered ViewModel of type {registration.ViewModelType.Name} to page {registration.ViewType.Name}.");
}
private static TView GetViewInstance <TView>(
INavigationRegistration registrationInfo)
where TView : Page
{
return(registrationInfo.ResolveViewUsingDependencyInjection
?
(TView)dependencyResolver.Resolve(
registrationInfo.ViewType)
:
(TView)Activator.CreateInstance(
registrationInfo.ViewType));
}
private static void RemoveRegistration(
INavigationRegistration registration)
{
var cachedPage = ContentCache.FirstOrDefault(
cache => cache.Type == registration.ViewType);
if (cachedPage != null)
{
ContentCache.Remove(cachedPage);
}
NavigationRegistrations.Remove(registration);
Log?.Info($"Unregistered views from ViewModel of type {registration.ViewModelType.Name}.");
}
private static TView GetContentInstance <TView>(
INavigationRegistration registration)
where TView : FrameworkElement
{
if (registration.ResolveViewUsingDependencyInjection)
{
return((TView)dependencyResolver.Resolve(
registration.ViewType));
}
else
{
return((TView)Activator.CreateInstance(
registration.ViewType));
}
}
private static bool TryGetRegistration(
Type viewModelType,
out INavigationRegistration registrationInfo)
{
if (!IsRegistered(viewModelType))
{
registrationInfo = null;
return(false);
}
registrationInfo = NavigationRegistrations.OfType <RegistrationInfo>()
.FirstOrDefault(registration =>
registration.ViewModelType == viewModelType);
return(registrationInfo != null);
}
private static bool TryGetRegistration(
Type viewModelType,
Type viewType,
out INavigationRegistration registrationInfo)
{
if (!IsRegistered(viewModelType, viewType))
{
registrationInfo = null;
return(false);
}
registrationInfo = NavigationRegistrations.FirstOrDefault(registration =>
registration.ViewModelType == viewModelType &&
viewType.IsAssignableFrom(registration.ViewType) &&
registration.Condition?.Invoke() != false);
return(registrationInfo != null);
}
private static bool TryGetRegistration(
Type viewModelInterfaceType,
out INavigationRegistration registrationInfo)
{
if (!IsRegistered(viewModelInterfaceType))
{
registrationInfo = null;
return(false);
}
registrationInfo = NavigationRegistrations.OfType <NavigationRegistration>()
.FirstOrDefault(registration =>
registration.ViewModelType == viewModelInterfaceType &&
registration.Platform.ToXamarinPlatform() == Device.RuntimePlatform);
return(registrationInfo != null);
}
private static void CreateCachedContent(
INavigationRegistration registration)
{
if (!Configuration.CacheContent)
{
return;
}
if (Configuration.ContentTypesToExcludeFromCaching?
.Contains(registration.ViewType) == true)
{
return;
}
var content = GetContentInstance <FrameworkElement>(
registration);
var cachedContent = new CachedContent(content);
ContentCache.Add(cachedContent);
}
/// <inheritdoc cref="CodeMonkeys.Navigation.INavigationService.Register(INavigationRegistration)" />
public void Register(
INavigationRegistration registrationInfo)
{
if (registrationInfo is NavigationRegistration xamarinRegistration)
{
if (xamarinRegistration.Platform != DevicePlatforms.All &&
Device.RuntimePlatform.ToDevicePlatform() != xamarinRegistration.Platform)
{
return;
}
}
RegisterInternal(registrationInfo);
if (registrationInfo.PreCreateInstance)
{
Task.Run(() => CreateCachedPage(registrationInfo.ViewType));
}
Log?.Info($"Registered ViewModel of type {registrationInfo.ViewModelType.Name} to page {registrationInfo.ViewType.Name}.");
}
private static void RegisterInternal(
INavigationRegistration registration)
{
_semaphore.Wait();
try
{
if (TryGetRegistration(
registration.ViewModelType,
registration.ViewType,
out var registrationInfo))
{
NavigationRegistrations.Remove(registrationInfo);
}
NavigationRegistrations.Add(registration);
}
finally
{
_semaphore.Release();
}
}
private static void RegisterInternal(
INavigationRegistration registration)
{
_semaphore.Wait();
try
{
if (!Configuration.AllowDifferentViewTypeRegistrationForSameViewModel &&
TryGetRegistration(
registration.ViewModelType,
out var registrationInfo))
{
NavigationRegistrations.Remove(registrationInfo);
}
NavigationRegistrations.Add(registration);
}
finally
{
_semaphore.Release();
}
}
